4.4 – CONVEX MIRRORS p. 318 – 320

HOW ARE CONVEX MIRRORS DIFFERENT FROM CONCAVE ONES?  Both mirrors are curved  Convex is shaped so the middle of the mirror is pushing out toward you

 Convex mirrors are aka diverging mirrors  because reflected rays spread apart (diverge) after hitting the mirror

CONVEX MIRRORS PRODUCE VIRTUAL IMAGES  Rules for drawing images produced in convex mirrors are the same as those for concave mirrors  images that form are always virtual  must extend reflected rays behind the mirror to make them intersect

DRAWING RAY DIAGRAMS  F and C are located on the non-reflective side of the mirror (because it’s a convex mirror)  When drawing ray diagrams, rays touch the top of the object, and then travel to F or C as though the incident or reflected ray travels through F or C  but they don’t actually

RULES TO DRAWING A RAY DIAGRAM 1. Rays parallel to the PA reflect as if they had gone through F 2. Rays appearing to pass through F reflect back parallel to the PA (opposite of #1) 3. [Rays that appear to pass through C reflect back along the same path] p. 320

STEPS:  Draw a ray from the top of the object: 1. Parallel to the PA, which reflects off mirror as if it had gone through F 2. As though it will pass through F, which reflects back parallel to the PA (opposite of #1) 3. [As though it will pass through C, which reflects back along the same path] p. 320

IMAGE CHARACTERISTICS  L – closer to mirror  O – upright  S – smaller  T – virtual (you have to extend the reflected rays behind the mirror so they intersect)

DIFFERENCES BETWEEN IMAGES FORMED IN CONCAVE & CONVEX MIRRORS LOSTLOST

WHAT ARE CONVEX MIRRORS USEFUL FOR?  Convex mirrors produce images that are smaller, but give a wider field of view than in concave mirrors  Used for:  safety (car side mirrors and hallways with sharp, “blind” corners)  security (inspecting underneath cars at the border, in retail stores)

OBJECTS IN CONVEX MIRRORS ARE CLOSER THAN THEY APPEAR  Objects look farther away then they actually are because the image that forms in the mirror is smaller